Power from an engine is typically delivered to vehicle wheels to propel a vehicle. Additionally, engine power may be used to drive ancillary vehicle accessories such air conditioning and alternators. However, some vehicles include a power take off port located in the vehicle driveline between the engine and the wheels. The power take off can be a source of power to a device that is external to the vehicle or to a device that may not be incorporated into a typical passenger vehicle. For example, a power take off port may power a hydraulic pump that lifts a snow plow or a hydraulic motor that turns a cement mixer. However, typical power take off ports are limited to rotating in a single direction. Further, wheel torque provided to a driveline may be reduced when some power take off (PTO) devices are engaged.
The inventors herein have recognized the above-mentioned disadvantages and have developed a method of operating a PTO, comprising: rotating a PTO output via rotating a PTO power source in a first direction; and reversing rotation of the PTO output via rotating the PTO power source in a second direction different than the first direction, the PTO power source positioned in a vehicle driveline.
By providing power to a PTO output via a driveline integrated starter generator it may be possible to provide a reversing PTO output and a wheel torque that follows a desired wheel torque even in the presence of a PTO load. For example, by decoupling a DISG from an engine via a driveline disconnect clutch, it is possible to provide forward and reverse PTO output rotation. Additionally, when a driveling clutch positioned between the DISG and the engine is closed, it may be possible to provide additional torque to a vehicle driveline while the PTO is being operated so that the actual wheel torque matches a desired wheel torque.
The present description may provide several advantages. Specifically, the approach may improve PTO functionality. Further, the approach may improve vehicle drivability during PTO operation. Further still, the approach may improve PTO operation communications to an operator.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.